Former British Ambassador Craig Murray, who is warning of an imminent raid on the Ecuadorean embassy to extract Julian Assange.

As Ecuador puts its weight behind protecting Julian Assange, tension is building in the tug-of-war between the small South American country and the United Kingdom over the WikiLeaks founder's fate. And according to one former UK ambassador, it might be about to reach a breaking point.

Hours before Ecuador's announcement that it would grant asylum to Assange, a former UK ambassador warned in a blog post that he's learned the British government is planning to raid the embassy to remove the Australian, who is wanted for questioning on sex crime charges allegations in Sweden but believes he will be extradited to the U.S. to face potential charges related to his publishing of troves classified American government documents.

Craig Murray, a former ambassador to Uzbekistan, writes that he "returned to the UK today to be astonished by private confirmation from within the FCO that the UK government has indeed decided – after immense pressure from the Obama administration – to enter the Ecuadorean Embassy and seize Julian Assange."

"This will be, beyond any argument, a blatant breach of the Vienna Convention of 1961, to which the UK is one of the original parties and which encodes the centuries – arguably millennia – of practice which have enabled diplomatic relations to function," Murray added.

Murray's comments add confirmation to a statement from the Ecuadorean government Wednesday that it was "deeply shocked" by the British government's alleged plan to enter the embassy and arrest Assange, who violated his house arrest and bail agreement to take up resident in the embassy two months ago.

"We are deeply shocked by British government’s threats against the sovereignty of the Ecuadorian Embassy and their suggestion that they may forcibly enter the embassy," the embassy wrote in a statement. "...the Ecuadorian Government has acted honourably in all our attempts to seek a resolution to the situation. This stands in stark contrast to the escalation of the British Government today with their threats to break down the door of the Ecuadorian Embassy."

On Thursday, Ecuadorean foreign minister Ricardo Patiño issued a statement that Ecuador would grant asylum to Assange, who the Ecuadorean government believes faces persecution for his controversial publications. "He doesn’t want to face political persecution that will violate his rights and threaten his life and freedom," reads a translation of Patiño's statement. “Asylum is a fundamental human privilege… There should be no distinction of race, gender… political opinion.”

The U.K. foreign office responded to the decision on Twitter, saying it was "disappointed" by Ecuador's decision, and would remained "committed to a negotiated solution that allows us to carry out our obligations under the Extradition Act."

The standoff leaves Assange stranded in the Ecuadorean embassy. Despite Ecuador's offer of asylum, London police would have to grant Assange safe passage to Ecuador, which seems very unlikely.

As former ambassador Murray wrote of a potential raid, activists, media, and police gathered outside the Ecuadorean embassy Wednesday.

Murray, who left the U.K. foreign office in 2004 and has criticized the British government's alliance with an Uzbek regime that tortured its citizens, warned that a raid on Ecuador's embassy to seize Assange would have enormous diplomatic implications. He points the case of dissident Chen Guangchen, who took recently refuge in the American embassy in Beijing before seeking asylum in the U.S. Even then, he points to China's respect for the sovereignty of the American embassy.

"Even during the decades of the Cold War, defectors or dissidents were never seized from each other’s embassies," he writes. "This terrible breach of international law will result in British Embassies being subject to raids and harassment worldwide."